The design of semiconductor devices has progressed to the point where switching times on the order of 100 picoseconds, or less, are routinely achieved (1 picosecond=10.sup.-12 sec.). In accordance with well-known principles, in order to test such devices, pulses having rise-times on the order of 10 picoseconds, or less, are required.
Unfortunately, it has not been possible to generate such short rise-time pulses with prior art pulse generators. U.S. Pat. No. 3,360,678, which issued on Dec. 26, 1967, to Q. A. Kerns, discloses a fast pulse generator which uses an electron beam to cause an arc breakdown across the gap region of the center conductor of a coaxial cable. However, the fastest pulse that Kerns can develop has a rise-time in the order of 1 nanosecond (1,000 picoseconds) which is useless for testing semiconductor devices that can switch in 100 picoseconds. U.S. Pat. No. 4,140,917, which issued on Feb. 20, 1979 to Maurice Weiner discloses a fast rise-time spiral pulse stripline generator but, again, only pulses in the order of several nanoseconds are achieved by this apparatus.